The Reliability of the Transportation System and Its Influence on the Choice Behaviour

The Reliability of the Transportation System and Its Influence on the Choice Behaviour


A Koenig, ETHZ, CH



Our society and especially today?s business life is structured by time-tight schedules. Time has been established as an expensive good. Transportation planning takes account of the time spent and its value.

It is in the usual choice models such as destination-, route- or mode-choice models. Many of these choice models calculate a utility for each alternative and choose the one which shows the highest utility. Currently time is included in the utility function, as either the mean trip duration or the mean speed of vehicles.

But what is the utility of a fast car while it is standing in traffic congestion? When people choose a mode to go somewhere they think not only about the normal duration of a trip but also about the reliability of the arrival time in the particular situation. Still the mentioned choice models generally do not contain a term concerning how reliable the alternatives are. One reason for not considering this item on the problem of how to measure and describe reliability for the users of transportation systems. The SVI-Research Project "The Reliability of the Transportation System and its Influence on the Choice Behavior" focuses on this problem.

The measurement instrument is a survey, which was conducted during 2001. It considered different methods of questioning as well as several types of presentation. For the study there was the opportunityto use addresses of respondents from a continuous Swiss survey, who had initially been contacted by theSwiss Federal Railways. Almost 1000 persons answered the questionnaire (a response rate of 65 %). The core of the questionnaire are three Stated-Preference-Experiments, two route choice and one combined route- and mode choice.

The results of the survey were modelled by using the MNL approach.The presentation will be structured as followed:

Introduction into the topic:

* Intention of the study
* Definition of Reliability

Presentation of the survey

* Structure
* Contents

Model estimation

* Basics
* Implementation
* Results (initial estimation of a "value of reliability")


Association for European Transport